________________________________________________________________________________________

Home / Engines / Briggs and Stratton Engines / Briggs and Stratton 31H777

Briggs Stratton 31H777 Maintenance

Engine Model: Briggs and Stratton 31H777
Engine Type: 4-cycle single cylinder OHV vertical shaft gasoline engine
Total Displacement: 30.6 cu.in (502 cc)
Rated Engine Power: 18 Hp (13.3 kW) at 3600 rpm
Fuel System: Float type carburetor with fixed main jet

Service Data

Cylinder Bore Inside Diameter (Maximum), in (mm) ................ 3.567 (90.60)
Cylinder Head (Max Out of Flatness), in (mm) ................ 0.004 (0.10)
Valve Clearance (Intake), in (mm) ................ 0.003-0.005 (0.08-0.13)
Valve Clearance (Exhaust), in (mm) ................ 0.005-0.007 (0.13-0.18)

Engine Oil and Filters

Engine Oil Type (Summer) ................ SAE 30, 10W-30
Engine Oil Type (Winter) ................ SAE 5W-30
API Service Classifications ................ SF, SG, SH, SJ or higher
Oil Capacity, qts (L) ................ 1.51 (1.42)
Oil Filter Part Number ................ 492932S
Air Filter Element Part Number ................ 698083

Ignition System

Spark Plug Type ................ Champion RC12YC
Spark Plug Gap, in (mm) ................ 0.03 (0.76)
Armature Air Gap, in (mm) ................ 0.010-0.014 (0.25-0.36)
Spark Plug Torque, Nm (lb-ft) ................ 20 (14.8)

Service Intervals

Check Engine Oil Level ................ Every 10 hours
Clean Air Filter Cartridge ................ Every 25 hours
Change Engine Oil ................ Every 50 hours
Replace Engine Oil Filter ................ Every 50 hours
Check and Adjust Spark Plug ................ Every 50 hours
Replace Fuel Filter ................ Every 100 hours
Replace Spark Plug ................ Every 100 hours
Replace Air Filter Cartridge ................ Every 100 hours
Clean Combustion Chamber ................ Every 200 hours
Check Carburetor Adjustment ................ Every 200 hours
Check and Adjust Idle Speed ................ Every 200 hours
Check and Adjust Valve Clearance ................ Every 200 hours

Replacement Parts

Air Filter (Cartridge). Part Number ................ 698083, 697153
Oil Filter. Part Number ................ 492932S, 696854
Fuel Filter. Part Number ................ 394358S, 691035
Spark Plug. Part Number ................ 691043, 491055S
Crankshaft Oil Seal (Mag). Part Number ................ 391086S
Crankshaft Oil Seal (PTO). Part Number ................ 795387
Cylinder Head Gasket. Part Number ................ 796584
Crankcase Gasket. Part Number ................ 697110

Tightening Torques

Air Cleaner Base, lb-ft (Nm) ................ 4.4 (6.0)
Alternator, lb-ft (Nm) ................ 1.5 (2.0)
Armature, lb-ft (Nm) ................ 2.2 (3.0)
Blower Housings, lb-ft (Nm) ................ 7.4 (10.0)
Blower Housing Brackets, lb-ft (Nm) ................ 7.4 (10.0)
Breather, lb-ft (Nm) ................ 2.2 (3.0)
Carburetor to Intake Manifold, lb-ft (Nm) ................ 5.9 (8.0)
Carburetor Solenoid, lb-ft (Nm) ................ 3.7 (5.0)
Connecting Rod, lb-ft (Nm) ................ 12.6 (17.0)
Control Bracket, lb-ft (Nm) ................ 2.2 (3.0)
Crankcase Sump, lb-ft (Nm) ................ 18.5 (25.0)
Cylinder Head, lb-ft (Nm) ................ 18.5 (25.0)
Cylinder Shield, lb-ft (Nm) ................ 3.7 (5.0)
Exhaust Manifold/Adapter, lb-ft (Nm) ................ 14.1 (19.0)
Flywheel Nut, lb-ft (Nm) ................ 100.0 (135.0)
Flywheel Fan, lb-ft (Nm) ................ 11.9 (16.0)
Fuel Pump, lb-ft (Nm) ................ 7.4 (10.0)
Governor Lever Nut, lb-ft (Nm) ................ 3.7 (5.0)
Intake Manifold to Cylinder Head, lb-ft (Nm) ................ 7.4 (10.0)
Muffler, lb-ft (Nm) ................ 7.4 (10.0)
Oil Drain Plug, lb-ft (Nm) ................ 8.1 (11.0)
Oil Fill Tube, lb-ft (Nm) ................ 7.4 (10.0)
Oil Pump Cover, lb-ft (Nm) ................ 7.4 (10.0)
Regulator/Rectifier, lb-ft (Nm) ................ 3.7 (5.0)
Rewind Starter, lb-ft (Nm) ................ 2.2 (3.0)
Rocker Ball Set Screw or Nut, lb-ft (Nm) ................ 3.7 (5.0)
Spark Plug, lb-ft (Nm) ................ 14.8 (20.0)
Starter Motor, lb-ft (Nm) ................ 11.9 (16.0)
Rocker Cover, lb-ft (Nm) ................ 5.2 (7.0)

________________________________________________________________________________________

________________________________________________________________________________________

Engines Technical Specifications
BRIGGS 28S777 BRIGGS 31H777 BRIGGS 31P977 BRIGGS 31Q777
HONDA GC135 HONDA GCV160 HONDA GS190 HONDA GX340
KOHLER CH18S KOHLER CH680 KOHLER CV460S KOHLER SV735S
KUBOTA D1305 KUBOTA D1503 KUBOTA V1903 KUBOTA 2003T

Lawn and Garden Tractors Technical Specs
JOHN DEERE 314 JOHN DEERE D130 JOHN DEERE E150 JOHN DEERE L118
KUBOTA G5200 KUBOTA GR2100 KUBOTA T1400 KUBOTA T1560
FORD 140 FORD GT95 FORD LGT14D FORD LGT165
CRAFTSMAN GT5000 CRAFTSMAN LT2500 CRAFTSMAN T2000 CRAFTSMAN YT3000
CUB CADET 782D CUB CADET 1811 CUB CADET 2186 CUB CADET LT1045
HUSQVARNA CTH151 HUSQVARNA TC138 HUSQVARNA TS142T HUSQVARNA GT2254

Farm Tractors Technical Specifications
JD 1026R JD 3650 JD 6400 JD 7810
KUBOTA B7500 KUBOTA L245 KUBOTA L2250 KUBOTA M4072
FORD 1320 FORD 2810 FORD 3930 FORD 5600
MF 250 MF 690 MF 3060 MF 6180
NH TC48DA NH M100 NH T7550 NH 8560
CASE IH 495 CASE IH 1255XL CASE IH 2140 CASE IH 2294